Better RTK GPUS support for Ardupilot
Choosing between L1, L2, L5
Most RTK solutions support L1/L2.
When choosing GPSs for base station and rover (drone), ensure both support the same frequency bands.
If, for example, drone supports L1,L5 and base supports only L1; we are effectively handicapping the drone to just L1
RTK requires common frequency bands for performing the computation.
If using L1,L2 on drone and L1,L2 on base; both the bands are tracked by the drone and RTK will be able to perform at dual frequency and better performance.
Don’t yet know if L5 has a significant advantage over L1/L2 when used in combination with RTK.
Dead Reckoning Modules
These modules use info from other sensors (gyro, accelero, etc) to calculate position.
This is useful when the GPS position is difficult, eg: tunnels, parking lots.
List of GPSes
Note about Holybro and Ublox: many of the Holybro GPSes incorporate Ublox gps tech.
$60: PX1125R L1/L5 RTK
F9P
L1/L5
$350-400: https://holybro.com/products/h-rtk-f9p-gnss-series?variant=41466787201213
https://www.u-blox.com/en/product/neo-f9p-module?legacy=Current#Product-Selection (contact them for price)
ZED vs NEO:
NEO seems to be super precise, involving automated industrial moving machinery :|
ZED is about enable mobile customers access to L1/L5.
Three variants: only drone, only base, both base and drone.
M8P
We already have some of these.
L1 only
$199: https://holybro.com/products/h-rtk-m8p-gnss-series(discontinued on Holybro site)
Three variants: only drone functionality both base and drone.
NEO-D9S
Says L band, it means all L1,2,3 and more!.
Support some form of correction data, not sure if it’s same as rtk
ZED F9R
Supports usage as RTK rover, not sure if it can be used as base station.
Name | Cost | Documentation, Compatibility | Reliability, Bands | Extra Notes |
---|---|---|---|---|
NEO F9P | $350 | Very Good | Very Good (L1/L5) | Top of the line You get what you pay for |
ZED F9P | $129 | Good | Very Good (L1/L5) | Top of the line You get what you pay for |
NEO M8P | $129-199 | Very Good | Bad, L1 only | Unreliable under cloudy weather |
NEO D9S | $48.85 (Prices may Vary) | Okay | Good (Untested), All L-bands | Rover Only Less community experience |
ZED F9R | $150-220 | Okay | Good (Untested), L1/L2 | Rover Only |
PX Family (1125R, 1172R, 1122R) | $60-120 | Very Bad | Untested, L1/L2/L5 Depending on model | Non existent documentation We’ll be going in blind for these ones |